Process for obtaining fast tints on wool



Patented Mar. 6, 1934 UNITED STATES PROCESS FOR OBTAINING FAST TINTS ON WOOL Albert Landolt, Basel, Switzerland, assignor to the firm of Society of Chemical Industry in Basle,

Basel, Switzerland No Drawing.

Application March 7, 1932, Serial No. 597,428. In Switzerland March 28, 1931 4 Claims.

It has been found that valuable, more or less reddish-blue and greenish-blue tints are obtained on wool by first grounding the wool with non-sulfonated arylides of 2:3-hydroxy-naphthoic acid in baths containing free caustic alkali, and under quite definite conditions which will be explained later, and then developing the wool grounded in this manner with such diazo compounds which correspond to the general formula in which the two benzene nuclei bear, besides the --N=NOH group, no other groups occasioning solubility in water or aqueous alkali solutions, such as SOaH, COOH or OH groups. A number of such diazo compounds are disclosed below.

As regards the special grounding conditions, they are dependent on the following circumstances, which partially have been unknown up to now. It is known that caustic alkali affects the wool very easily, especially at raised temperatures and already at moderate concentration. On the other hand it has been found that the arylides of 2:3-hydroxynaphthoic acid, when dissolved in water, with aid of just the sufiicient quantity of caustic alkali, have no or only a very slight afiinity for W001, but that in the presence of an excess of caustic alkali the affinity for wool increases considerably. This afiinity now permits, provided that suflicient alkali is present in the grounding bath, to extensively exhaust the grounding bath, which, on the one hand, has the advantage that no standing baths must be used, and on the other, that by the subsequent coupling on the fiber dyeings are obtained which are fast to rubbing.

It has now been ascertained on the basis of a great number of experiments that the following points have to be considered in order to obtain useful dyeings on the one hand, and to prevent injuring the wool fiber, on the other hand. The proportion of the grounding liquor to the goods ought not to be much smaller than 1:6, and not much greater than 1:50. The grounding bath should not contain more arylide than 5 per cent. calculated on the weight of the wool. Finally, the quantities of sodium hydroxide used should amount to about the 1.5 to 2.5 fold of the weight of the arylide used. Within these extreme combinations the conditions may, of course, vary appropriately according to the existing apparatuses.

The following examples illustrate the lnventionz- Example 1 10 kilos of loose wool are grounded in a liquor containing per 300 litres of water, 0.3 kilo of the para-chloranilide of 2:3-hydroxynaphthoic acid, 1.5 kilo of Turkey red oil, 1.2 litres of caustic soda solution of 36 B., 6 litres of sulfite cellulose solution freed from lime of 40 per cent. strength and 6 kilos of sodium chloride. The wool is treated with the circulating liquor for hour at a temperature of 45 C., then centrifuged and developed in the following developing liquor:

300 litres of water of 10 C.

0.3 kilo of the diazo-compound from 4-amino- 4'-methoxy-diphenylamine.

0.5 kilo of sodium bicarbonate.

The treatment is continued for minutes and the goods are then washed and soured with 0.4

kilo of sulfuric acid in 300 litres of water for 20 minutes at 80 C. In this manner there is obtained a deep, bloomy blue of good fastness to fulling, potting, acid boiling, steaming and light.

When the operation is conducted as prescribed in Example 5 of French specification No. 665,265 there is obtained a feeble, unsightly blue-grey.

Example 2 For the dyeing of 10 kilos of previously washed loose wool, a dyeing bath is prepared as follows:

0.2 kilos of the cz-llfiDhthYltLIIlldB of 2:3-hydroxynaphthoic acid made into a paste with sulforicinate or alcohol,

1 litre of caustic soda solution of 36 B.

100 litres of water 2 kilos of sulfite cellulose waste liquor 3 kilos of calcined Glauber's salt.

The wool is treated with the circulating liquor for half an hour at ordinary temperature, then removed, centrifuged, and developed in the following bath 0.4 kilos of the diam-compound from 4'-ethoxy- 4-amino-diphenylarnine 0.2 kilos of acetic acid of 40 per cent. strength 100 litres of water.

The treatment in this bath is to last 20 minutes whereupon the dyeing process is completed as described in Example 1. The wool is dyed a deep blue of good fastness.

Example 3 20 kilos of wool yarn are moved about for of an hour, at 0., in a dyeing bath consisting of 1000 litres of water 1 kilo of the anilide of 2:3-hydroxynaphtholc acid 5 litres of caustic soda solution of 36 B.

20 kilos of sulfite cellulose waste liquor 30 kilos of calcined Glaubers salt.

After centrifuging the yarn is developed for half an hour with 4 per cent. of the diazo-conipound from 4- amino-4'-methoxy-diphenylamine calculated on the weight of the wool, and

2 per cent. of acetic acid of 40 per cent. strength as described in Example 2. The dyeing process is then completed as described in Example 1. The wool is dyed a deep blue of good fastness.

Similar blue tints are obtained with other arylides of 2:3-hydroxynaphthoic acid containing no OH-group in the aryl radicle, such as the anilide, the a-naphthylamide, the 5- or -chloro- 2-toluidide, the ortho-, metaor para-anisidide, the orthoor meta-chloranilide, the metaor para-toluidide, the 4-chloranisidide, the metaxylidide, the orthoor para-phenetidide, the meta-phenylenediimide, the toluylenediimide, the 2:5-dimethoxyanilide or the like.

Also more or less greenish or reddish blue tints are obtained with other diazotized 4-aminodiphenylamine derivatives, such as 4-aminodiphenylamine, 4,-amino-2'-methoxy-5-chloro-diphenylamine, 4-amino-2':5'-dimethoxyor diethoxydiphenylamine or the like.

Particularly advantageous are the substitution products of 4-diazo-diphenylamine whose substituents are alkoxy groups.

What I claim is:-

1. A process for obtaining fast tints on wool by means of non-sulfonated arylides of 2:3-hydroxynaphthoic acid containing no OHgroup in the aryl radicle and such diazo-compounds which correspond to the general formula in which the two benzene nuclei bear, besides the -N=N-OH group, no other groups occasioning solubility in water and in aqueous alkali solutions, wherein the wool is grounded in a grounding bath under the following conditions:

(a) proportion of goods to grounding liquor 1:5 to 1:50,

(b) the grounding bath does not contain more arylide than 5 per cent. of the weight of the wool to be grounded,

(c) the quantities of sodium hydroxide used correspond to about the 1.5 to 2.5 fold quantity of the arylide used.

2. A process for obtaining fast tints on wool by means of non-sulfonated arylides of 2:3-hydroxynaphthoic acid containing no OH-group in the aryl radicle and such diazo-compounds which correspond to the general formula in which the two benzene nuclei bear, besides the -N=NOH group, no other groups occasioning solubility in water and in aqueous alkali solutions, and as substituents at the most two alkoxy groups, wherein the wool is grounded in a grounding bath under the following conditions:

(a) proportion of goods to grounding liquor 1:5 to 1:50,

(b) the grounding bath does not contain more arylide than 5 per cent. of the weight of the wool to be grounded,

(c) the quantities of sodium hydroxide used correspond to about the 1.5 to 2.5 fold quantity of the arylide used.

3. A process for obtaining fast tints on wool by means of non-sulfonated arylides of 2:3-hydroxynaphthoic acid containing no OH-group in the aryl radicle and a diazo-compound corresponding to the formula wherein the wool is grounded in a grounding bath under the following conditions:

(a) proportion of goods to grounding liquor 1:5 to 1:50,

(b) the grounding bath does not contain more arylide than 5 per cent. of the weight of the wool to be grounded,

(c) The quantities of sodium hydroxide used correspond to about the 1.5 to 2.5 fold quantity of the arylide used. 4. A process for obtaining fast tints on wool by means of non-sulfonated arylides of 2:3-hydroxynaphthoic acid containing no OH-group in the aryl radicle and a diazo-compound corresponding to the formula of the arylide used,

(c) the grounding must be continued until the grounding bath is practically exhausted.

ALBERT LANDOLT. 

